Guillaume Maka

If you already have some knowledge in C# you can go with ASP.NET Core MVC and continue your learning path (if you liked the language in the first place). but both solution will allow you to build an ERP/eCommerce project.

There is not too much difference between Django and ASP.Net Core MVC both follow the same design principles for building application, they both flexible, provide a lot of library, have a great community support..

The downside (thats my opinion) with ASP.Net Core you are going to follow the Microsoft philosophy of doing thing and you will mostly by tight to there products lineup. Instead of Django where you'll have more freedom.

If your concern is - Robustness: both are valid choice - Long Term Support: Go ASP.Net why? Because the project is maintained by Microsoft the chance that the project go unmaintained is low. Django is more Open Source we never know when it will stop be maintained.

The best I can give you, it's to try both and make your own opinion. Build a Proof of Concept and see by yourself.

If your goal is to display data MongoDB is a good choice in term of storage and cost. The shared instance mostly fit entry level application.

If your unstructured data schema doesn't chance much (fields add/remove) you can even plug-in the GraphQl Api implementation with MongoDB Realm, also MongoDB Realm offer a variety of authentication providers (JWT/JWKS, apiKey, custom scheme). If you go with GraphQL you can skip Django (unless you have custom business logic) and just build a frontend app to display your data (VueJS, React, Svelte, jQuery, vanilla javascript, etc...).

As far as I understand, Kafka is a like a persisted event state manager where you can plugin various source of data and transform/query them as event via a stream API. Regarding your use case I will consider using RabbitMQ if your intent is to implement service inter-communication kind of thing. RabbitMQ is a good choice for one-one publisher/subscriber (or consumer) and I think you can also have multiple consumers by configuring a fanout exchange. RabbitMQ provide also message retries, message cancellation, durable queue, message requeue, message ACK....

Backend/Frontend (Unified): I would recommend Django in your use case. Django have a lot of components out of the box.

Mix SPA + REST Api (w/wo GraphQL) - SPA: Vue + Vuex (Checkout Nuxt.JS) | React + Redux - Django (django-rest-framework) or Node.JS (koa|express|hapi)

First I would ask you: Do you really need to go the full Single Page Application way ?

In my opinion the answer is No.

Regarding the database: - Django -> Postgres - Node.JS -> Postgres / MongoDB (Node.JS friendly)

I throw away MSSQL/Oracle of the discussion too much power for such thing, unless if your IT infrastructure provide it. So ask the IT what databases are available and use them. No need to add new technologies to the infrastructure.